Data.AVar.Unsafe

Data.AVar.Unsafe has a similar interface to Data.AVar, but instead of letting the user handle exceptions from Eithers, it will throw exceptions caught by the variable.

Documentation

data AVar a

AVars are the means through which communication with the variable are conducted. They contain a Chan that is connected to the variable, and is read by the variable's handler function.

data Result

Constructors

OK

getAVar :: AVar a -> IO a

getAVar reads the current value inside the AVar.

putAVar :: AVar a -> a -> IO ()

putAVar replaces the currect value in the variable with the given x

modAVar :: AVar a -> (a -> a) -> IO ()

modAVar takes a function from a to a, and modifies the variable. It will throw any exceptions caught by the variable when applying the function.

modAVar' :: AVar a -> (a -> (a, b)) -> IO b

modAVar' is like modAVar, but it modifies the variable, along with returning a result of type b. It also throws any errors caugh by the variable.

justModAVar :: AVar a -> (a -> a) -> IO ()

justModAVar will attempt to run the given function on the variable. It does not report back on its sucess or failure, and if the function produces an exception, the variable is left unchanged. It should be used when you just want to modify the variable, and keep running, without waiting for the action to complete.

condModAVar :: AVar a -> (a -> Bool) -> (a -> a) -> (a -> a) -> IO Bool

condModAVar applies the first finction to the current value in the AVar, and will modify the value using the second function if it results in True, or the third function if it results in Fasle.

swapAVar :: AVar a -> a -> IO a

swapAVar takes a new value, puts it into the AVar, and returns the old value.

newAVar :: a -> IO (AVar a)

newAVar creates a new variable. It forks off the handler that does the work for the variable itself and creates a new AVar.